Congo River | river, Africa | Britannica.com Congo River Livingstone Falls Congo River, formerly Zaire River, river in west-central Africa . With a length of 2,900 miles (4,700 km), it is the continent’s second longest river, after the Nile . It rises in the highlands of northeastern Zambia between Lakes Tanganyika and Nyasa (Malawi) as the Chambeshi River at an elevation of 5,760 feet (1,760 metres) above sea level and at a distance of about 430 miles (700 km) from the Indian Ocean . Its course then takes the form of a giant counterclockwise arc, flowing to the northwest, west, and southwest before draining into the Atlantic Ocean at Banana (Banane) in the Democratic Republic of the Congo . Its drainage basin , covering an area of 1,335,000 square miles (3,457,000 square km), takes in almost the entire territory of that country, as well as most of the Republic of the Congo , the Central African Republic , eastern Zambia , and northern Angola and parts of Cameroon and Tanzania .

The Congo River basin and its drainage network. Encyclopædia Britannica, Inc. With its many tributaries, the Congo forms the continent’s largest network of navigable waterways. Navigability, however, is limited by an insurmountable obstacle: a series of 32 cataracts over the river’s lower course, including the famous Inga Falls . These cataracts render the Congo unnavigable between the seaport of Matadi , at the head of the Congo estuary, and Malebo Pool , a lakelike expansion of the river. It was on opposite banks of Malebo Pool—which represents the point of departure of inland navigation—that the capitals of the former states of the French Congo and the Belgian Congo were founded: on the left bank Kinshasa (formerly Léopoldville), now the capital of the Democratic Republic of the Congo, and on the right bank Brazzaville , now the capital of the Republic of the Congo. The Amazon and the Congo are the two great rivers of the world that flow out of equatorial zones where heavy rainfall occurs throughout all or almost all of the year.

Upstream from Malebo Pool, the Congo basin receives an average of about 60 inches (1,500 mm) of rain a year, of which more than one-fourth is discharged into the Atlantic. The drainage basin of the Congo is, however, only about half the size of that of the Amazon, and the Congo’s rate of flow—1,450,000 cubic feet (41,000 cubic metres) per second at its mouth—is considerably less than the Amazon’s flow of more than 6,180,000 cubic feet (175,000 cubic metres) per second. Similar Topics Niger River While the Chambeshi River, as the remotest source, may form the Congo’s original main stream in terms of the river’s length, it is another tributary—the Lualaba , which rises near Musofi in southeastern Democratic Republic of the Congo—that carries the greatest quantity of water and thus may be considered as forming the Congo’s original main stream in terms of water volume.

When the river first became known to Europeans at the end of the 15th century, they called it the Zaire, a corruption of a word that is variously given as nzari, nzali, njali, nzaddi, and niadi and that simply means “river” in local African languages. It was only in the early years of the 18th century that the river was first called the “Rio Congo,” a name taken from the kingdom of Kongo that had been situated along the lower course of the river. During the period (1971–97) when the Democratic Republic of the Congo was called Zaire, the government also renamed the river the Zaire. Even during that time, however, the river continued to be known throughout the world as the Congo. To the literary-minded the river is evocative of the famous 1902 short story “ Heart of Darkness ” by Joseph Conrad . His book conjured up an atmosphere of foreboding, treachery, greed, and exploitation. Today, however, the Congo appears as the key to the economic development of the central African interior. Physical features Africa at Random: Fact or Fiction?

Physiography The expression “ Congo basin ,” strictly speaking, refers to the hydrographic basin. This is not only vast but is also covered with a dense and ramified network of tributaries, subtributaries, and small rivers—with the exception of the sandy plateaus in the southwest. Britannica Stories Ringling Bros. Folds Its Tent The Congo basin is the most clearly distinguished of the various geographic depressions situated between the Sahara to the north, the Atlantic Ocean to the south and west, and the region of the East African lakes to the east. In this basin, a fan-shaped web of tributaries flows downward along concentric slopes that range from 900 to 1,500 feet (275 to 460 metres) in elevation and that enclose a central depression. The basin itself stretches for more than 1,200 miles (1,900 km) from north to south (from the Congo–Lake Chad watershed to the interior plateaus of Angola) and also measures about 1,200 miles from the Atlantic in the west to the Nile-Congo watershed in the east.

The central part of the Congo basin—often called the cuvette (literally “saucer” or “shallow bowl”)—is an immense depression containing Quaternary alluvial deposits that rest on thick sediments of continental origin, consisting principally of sands and sandstones. These underlying sediments form outcrops in valley floors at the eastern edge of the cuvette. The filling of the cuvette, however, began much earlier. Boreholes have revealed that since late Precambrian times (i.e., since at least 570 million years ago) considerable sediment has accumulated, derived from the erosion of formations situated around the periphery of the cuvette. The arrangement of surface relief, thick depositional strata, and substratum in amphitheatre-like fashion around the main Congo channel, which has been uniform across time, is evidence of a persistent tendency to subsidence in this part of the continent. This subsidence is accompanied by uplifting on the edges of the cuvette, principally on its eastern side—which has also been influenced by the formation of the Western Rift Valley . From its sources to its mouth, the Congo River system has three contrasting sections—the upper Congo, middle Congo, and lower Congo.

The upper reaches are characterized by three features—confluences, lakes, and waterfalls or rapids. To begin with, several streams of approximately equal size unite to form the river. In a little more than 60 miles (100 km), the upper Lualaba joins the Luvua and then the Lukuga. Each stream for part of its course undergoes at least a lacustrine type of expansion, even when it does not form a lake. Thus, Lake Upemba occurs on the upper Lualaba; Lakes Bangweulu and Mweru occur on the Chambeshi–Luapula–Luvua system; and Lake Tanganyika , which is fed by the Ruzizi (flowing from Lake Kivu ) and by the Malagarasi , itself flows into the Lukuga. Rapids occur not only along the headstreams but also in several places along the course of the main stream. Navigation thus is possible only along sections of the upper Congo by vessels of low tonnage. Even so, these stretches are in danger of being overgrown by aquatic vegetation, particularly water hyacinths.

Connect with Britannica Editor Picks: Exploring 10 Types of Basketball Movies Upon leaving the Chenal, the Congo divides into two branches, forming Malebo Pool , a vast lacustrine area about 15 by 17 miles (24 by 27 km), which marks the end of the middle Congo. Immediately downstream occur the first waterfalls of the final section of the river’s course. Cataracts and rapids are grouped into two series, separated by a fairly calm central reach, in which the elevation drops from a little less than 900 feet (275 metres) to a few yards above sea level. The Congo’s estuary begins at Matadi, downstream from the rapids that close off the interior Congo; 83 miles (134 km) in length, it forms the border between Angola and the Democratic Republic of the Congo. At first the estuary is narrow—less than half a mile to about a mile and a half in width—with a central channel 65 to 80 feet (20 to 24 metres) deep, but it widens downstream of Boma .

There the river, obstructed by islands, divides into several arms, and in some places the depth does not exceed 20 to 25 feet (6 to 7.5 metres), which makes dredging necessary to allow oceangoing vessels to reach Matadi. Beyond the estuary’s mouth, the course of the Congo continues offshore as a deep underwater canyon that extends for a distance of about 125 miles (200 km). Page 1 of 6 Where does the Congo River start and end? | Reference.com Where does the Congo River start and end? A: Quick Answer The Congo River starts in central Africa in the country of The Democratic Republic of The Congo and ends in the country of Tanzania. It eventually feeds into the Atlantic Ocean. Full Answer The Congo River is the fifth longest river in the world and the second longest river in Africa behind the Nile River. It runs through a number of African countries, including the Central African Republic, Zambia, Cameroon, Angola and Tanzania. The length of the Congo river is 2,922 miles, and it is considered to be the strongest river on the African Continent. It was formerly known as the Zaire River.

Niger River | river, Africa | Britannica.com Niger River Alternative Titles: Isa Eghirren, Joliba, Kwarra, Kworra, Mayo Balleo, Quorra Related Topics Jebba Niger River, principal river of western Africa . With a length of 2,600 miles (4,200 km), it is the third longest river in Africa, after the Nile and the Congo . The Niger is believed to have been named by the Greeks. Along its course it is known by several names. These include the Joliba (Malinke: “great river”) in its upper course; the Mayo Balleo and the Isa Eghirren in its central reach; and the Kwarra, Kworra, or Quorra in its lower stretch. The Niger and Sénégal river basins and the Lake Chad basin and their drainage … Encyclopædia Britannica, Inc. The Niger River in the western region of Africa is used for irrigation, power production, and … Encyclopædia Britannica, Inc.

Physical features Physiography The Niger rises in Guinea at 9°05′ N and 10°47′ W on the eastern side of the Fouta Djallon (Guinea) highlands, only 150 miles (240 km) inland from the Atlantic Ocean . Issuing as the Tembi from a deep ravine 2,800 feet (850 metres) above sea level, it flows due north over the first 100 miles (160 km). It then follows a northeasterly direction, during the course of which it receives its upper tributaries—the Mafou , the Niandan, the Milo , and the Sankarani on the right and the Tinkisso on the left—and enters Mali . Just below Bamako , Mali’s capital, the Sotuba Dam marks the end of the upper river.

From there the Niger once dropped more than 1,000 feet (300 metres) in about 40 miles (60 km) into a valley formed by tectonic subsidence ; but the rapids in this stretch have been submerged by the waters backed up by the Markala Dam, located some 150 miles (240 km) downstream of the Sotuba Dam near Sansanding. In this stretch, at Koulikoro , the river takes a more east-northeasterly direction, and its bed becomes fairly free from impediments for about 1,000 miles (1,600 km). Similar Topics Kagera River At Mopti the Niger is joined by the Bani , its largest tributary on the right, after which it enters a region of lakes, creeks, and backwaters that is often called the “internal delta” of the Niger. These lakes are chiefly on the left bank and are connected to the river by channels that undergo seasonal changes in the direction of flow. At high water most of the lakes become part of a general inundation.

Largest of the lakes in this region is Lake Faguibine , which is nearly 75 miles (120 km) long, 15 miles (25 km) wide, and more than 160 feet (50 metres) deep in places. Fisherman setting his nets in the Bani River in Mali. © Index Open The labyrinth of lakes, creeks, and backwaters comes to an end at Kabara, the port of Timbuktu (Tombouctou). There, the river turns almost due east, passing its most northern point at latitude 17°05′ N. Some 250 miles (400 km) downstream from Timbuktu, a rocky ridge that obstructs the course of the river is pierced by a defile (narrow gorge) more than a mile long, with an average width of about 800 feet (240 metres) and a depth of more than 100 feet (30 metres) in places. At low water the strong current there endangers navigation.

A short way downstream the river turns to the southeast and widens considerably, flowing to Gao across a floodplain 3 to 6 miles (5 to 10 km) wide. This most northerly bend of the Niger flows through the southern fringe of the Sahara . The middle course of the Niger River is navigable to small craft during high water as far downstream as Ansongo —some 1,100 miles (1,770 km) in all. Below Ansongo, 430 miles (690 km) downstream from Timbuktu, navigability is interrupted by a series of defiles and rapids. The river becomes navigable to small vessels again at Labbezanga—from which it flows into Niger—and continues to be navigable to the Atlantic Ocean. Navigation is seasonal, however, because of the fluctuations in the water level in the rainy and dry seasons. Britannica Stories Ringling Bros. Folds Its Tent Downstream from Jebba , in Nigeria , the Niger enters its lower course, flowing east-southeast through a broad and shallow valley 5 to 10 miles (8 to 16 km) wide.

About 70 miles (110 km) from Jebba it is joined by the Kaduna River —an important tributary that contributes about one-fourth of the annual discharge of the river below the Niger-Kaduna confluence—and about 25 miles (40 km) above Lokoja the river turns to the south. At Lokoja the river receives the water of its greatest tributary, the Benue , thereby approximately doubling the volume of its annual discharge. At their confluence the Niger is about three-fourths of a mile (1 km) wide, and the Benue more than a mile. Together they form a lakelike stretch of water about two miles wide that is dotted with islands and sandbanks. From Lokoja downstream to the town of Idah , the Niger flows in a restricted valley, enclosed by hills and in some places flanked by sandstone cliffs up to 150 feet (45 metres) high. Between Idah and Onitsha the banks are lower and the country flatter.

At Onitsha, the largest town on the Niger’s banks in Nigeria and the third largest riverine town after Bamako and Niamey (Niger), the valley narrows as the river flows through what is probably a fault in the area’s sandstone. It emerges at Aboh, separating into many branches before reaching the Gulf of Guinea via Africa’s largest delta . Africa at Random: Fact or Fiction? The Niger delta , which stretches for nearly 150 miles (240 km) from north to south and spreads along the coast for about 200 miles (320 km), extends over an area of 14,000 square miles (36,000 square km). Within the delta the river breaks up into an intricate network of channels called rivers. The Nun River is regarded as the direct continuation of the river, but some of the other important channels include (from west to east) the Forcados , the Brass, the Sambreiro, and the Bonny. The mouths of these channels are almost all obstructed by sandbars.

The Forcados, for instance, which supplanted the Nun as the most traveled channel in the early 20th century, was in turn displaced by the Escravos River in 1964. The delta is being gradually extended seaward by the increments of silt brought down by the river, and mangrove swamps extend beyond its outer edge. Connect with Britannica Facebook Twitter YouTube Instagram Pinterest The Benue (meaning “Mother of Water” in the Batta language) rises at 4,400 feet (1,350 metres) above sea level on the Adamawa Plateau in northern Cameroon at about 7°40′ N and 13°15′ E. In its upper course, which extends north-northwest to its confluence with the Mayo Kébi, close to the town of Garoua , it is a mountain torrent, falling more than 2,000 feet (600 metres) over a distance of 110 miles (180 km). The river then turns westward into Nigeria and, for the greater part of its course, flows over a broad and fertile floodplain.

At Yola , a town 600 feet (180 metres) above sea level and some 850 miles (1,370 km) inland, the width of the river in flood is from 3,000 to 4,500 feet (910 to 1,370 metres). Near Numan , some 30 miles (50 km) downstream from Yola, the Benue is joined on its north bank by its most important tributary, the Gongola . Other important tributaries include the Shemankar, the Faro , the Donga, and the Katsina Ala . Together with its tributaries, the Niger drains a total area of some 730,000 square miles (1,900,000 square km). The Niger drainage system is bounded in the south by such highlands as the Fouta Djallon, the Banfora Cliffs in Burkina Faso , the Plateau of Yorubaland, and the Cameroon highlands. This southern rampart forms a watershed separating the rivers of the Niger system from others that flow directly southward to the Atlantic Ocean.

With the exception of such highlands as the Jos Plateau , the Iforas and Aïr massifs, and the Ahaggar Mountains to the north and east, the northern edge of the Niger basin is, however, less clearly defined than the southern edge. Climate Within the Niger basin, climate shows great variability. Mean annual precipitation levels decrease northward from more than 160 inches (4,100 mm) in the delta area to less than 10 inches (250 mm) in Timbuktu. Both the upper and the lower stretches of the river, however, drain areas with more than 50 inches (1,300 mm) of precipitation per year. The middle Niger is an area where precipitation decreases and is also the sector where the greatest amount of evaporation takes place. It is estimated that in the lake region the Niger loses some two-thirds of the annual volume of discharge that flows past Mopti. Hydrology Editor Picks: Exploring 10 Types of Basketball Movies Because of climatic variations the annual river flood does not occur at the same time in different parts of the basin. In the upper Niger the high-water discharge occurs in June, and the low-water season is in December.

In the middle Niger, a first high-water discharge—the white flood (so called because of the light sediment content of the water)—occurs soon after the rainy season between July and October; a second rise—the black flood (so called because of the greater sediment content)—begins in December with the arrival of floodwaters from upstream. May and June are the low-water months in the middle stretch. On the Benue there is only one high-water season. Because of the Benue’s more southerly location, this normally occurs from May to October—earlier than on the middle Niger. The lower Niger below its confluence with the Benue consequently has a high-water period that begins in May or June—about a month earlier than on the middle Niger—and a low-water period that is at least a month shorter, as the rains in the south start earlier. In January a slight rise occurs due to the arrival of floodwaters from the upper Niger. The difference between high and low water often measures as much as 35 feet (10 metres). Plant and animal life Along its course the Niger traverses virtually all the vegetational zones of western Africa.

The Fouta Djallon plateau, where the Niger rises, is covered by a type of sedge vegetation consisting of fine, wirelike tufts interspersed with bare rock surfaces. From the Fouta Djallon to well below the Niger’s confluence with the Benue, the river flows mainly through savanna grassland country. In the north the grass is short and discontinuous, and thorny shrub and acacia wood occur. In the south of the grassland region, tall, tussocky grass is interspersed with fairly dense wooded vegetation. About the latitude of Onitsha, the river enters the high rainforest belt, which merges below Aboh with the mangrove swamp vegetation of the delta. Trending Topics Eyjafjallajökull volcano Many varieties of fish are found in the Niger and its tributaries; the chief food species are catfish, carp, and Nile perch . Other Niger fauna include hippopotamuses, at least three different types of crocodiles (including the much-feared Nile crocodile), and a variety of lizards. There is a rich collection of birds.

Geese are found in the lake region, and herons, egrets, and storks are found both on the river and around the lakes. The striking crown bird is found wherever there is open ground in the grassland zone, and pelicans and flamingos are particularly associated with the upper Benue area. Smaller riverine species include white-headed plovers, crocodile birds, sandpipers, curlews , and green-red shanks. People and economy The Niger valley is sparsely settled, although there are population concentrations in the lake region and near the confluence of the Niger and Benue. From the 13th to 16th century the valley was the heartland of the Mali and Songhai empires, and some of the river towns date from this period. The ethnic pattern along the course of the river includes larger groups—such as the Bambara , the Malinke , the Songhai , and the Zarma (Zerma, Djerma)—occupying both sides of the river above the Nigerian boundary, below which there are many small ethnic groups. The Niger River at Mopti, Mali. © Brian A.

Vikander/West Light Fishing is an important activity along the length of the river system, especially during the dry season when the deep-sea and coastal fish catch is smallest. River fishing is a specialized occupation for certain peoples, such as the Bozo and Somono in the lake region, the Sorko on the middle Niger, the Kede and the Kakanda between Jebba and Lokoja, and the Wurbo and the Jukun on the Benue. The discovery and exploitation of petroleum in the delta region, however, has seriously disrupted fishing there; oil pollution has killed most of the fish, undermining the economy of the Ijo (Ijaw) people of the region. Irrigation The irrigation of the Niger valley—for the purpose of transforming it into a densely populated, agricultural corridor running through the interior of western Africa—has long been a goal of planners. In the 1930s the French colonial administration, for example, began to plan the irrigation of large areas in the lake region; a barrage at Sansanding that raised the level of the Niger was completed in 1947.

Feeder canals were constructed, and huge tracts of irrigated land now produce rice, cotton, sugarcane, and vegetables. The British colonial administration also encouraged irrigated rice cultivation in the Bida region. In Nigeria large-scale irrigation schemes have been developed since the 1960s on the Niger and some of its tributaries, notably the Sokoto, Kaduna, and Benue. The Niger is also a source of hydroelectricity. The largest project is the Kainji Dam in Nigeria, completed in the late 1960s. A 500-square-mile (1,300-square-km) lake has been created upstream, offering opportunities for fishing and irrigation. Other projects include the Sotuba and Markala dams in Mali and dams at Jebba (on the Niger) and Shiroro (on the Kaduna tributary) in Nigeria. Transportation Most of the Niger River—more than three-fourths of its total length—is used by commercial shipping. From the Atlantic Ocean to Onitsha the river is navigable by large vessels throughout the year.

From Onitsha to the confluence of the Benue and the Niger large vessels can move for 10 months of the year (June–March). Navigation in this stretch is made possible by the influx of water from the Benue River, which is at its high level in June. From Lokoja to Jebba the Niger is navigable to all craft only from October to mid-November. Thus, Jebba is in effect the head of navigation of the Niger waterway, although extreme fluctuation in water level at times constitutes a major handicap to vessels plying beyond Lokoja. Above Jebba the Niger is navigable only to smaller craft and is dependent locally on periods when water levels are adequate. A pirogue on the Niger River, Mali. Jon Ward Rail and road routes cross the river at many points. Railway bridges span the river at Kouroussa and Jebba, and another crosses the Benue at Makurdi . Road bridges over the Niger include those at Bamako, Niamey, Ségou , Malanville, Kainji, Jebba, Lokoja, and Onitsha and over the Benue at Makurdi, Numan, and Yola.

Ferries cross the Niger at Bamako, Gao, Niamey, Yelwa , and Idah and cross the Benue at Garoua. The main river ports are Koulikoro, Timbuktu, Baro , Onitsha, Burutu , and Koko . The coordination of multinational efforts to develop the Niger and its tributaries is the responsibility of the Niger River Commission, formed in 1963. The Commission has sponsored a study of the navigational possibilities of the middle Niger from Gao (Mali) to Yelwa (Nigeria). Moreover, in Nigeria several river basin development authorities have been established to develop more irrigation and fishing projects. Study and exploration It was not until the late 18th century that Europeans made systematic attempts to find the source, direction, and outlet of the Niger. In 1795 Mungo Park , a Scottish explorer, traveled overland from the Gambia region and reached the Niger near Ségou, where in July 1796 he established that the river flowed eastward.

In 1805 Park sailed more than 1,500 miles (2,400 km) down the river, seeking to reach its mouth, but he and his party were drowned in the rapids at Bussa (now covered by Lake Kainji). In 1822 another Scottish explorer, Alexander G. Laing , determined but did not visit the source of the river. In 1830 two English explorers, John and Richard Lander , established the lower course of the Niger by canoeing down the river from Yauri (now also covered by Lake Kainji ), to the Atlantic Ocean, via the Nun River passage. In the second half of the 19th century two German explorers, Heinrich Barth and Eduard R. Flegel , in separate travels established the course of the Benue from its source to its confluence with the Niger.

Additional Media Geography of the Congo River geography My Travel Photo » Rivers » Geography of the Congo River Geography of the Congo River View in a larger map FROM ITS SOURCE on a savanna plateau just south of Lake Tanganyika, the Congo River flows some 2,880 mile (4,630 kilometer) through equatorial africa before eventually emptying into the Atlantic Ocean. While no other major river in the world transects the equator even once, the Congo River twice crosses the equator in its journey to the sea. The river flows through an immense and relatively flat drainage basin that lies more than 1,000 foot (300 meter) above sea level. The Mitumba Mountains and the Ruwenzori Range form the eastern rim of the basin, while high plateaus rim the drainage basin in the north and south. A narrow westward outlet allows for the exit of the basin’s surface water. At 1.34 million square mile (3.46 million square kilometer), the Congo River basin is the second-largest drainage basin in the world and receives an average of 60 inch (152 centimeter) of rain annually.

Like its river and many tributaries in the region, the entire Congo basin is difficult to traverse. This significant precipitation total is attributable to the fact that the river flows through both the Northern and Southern Hemispheres in a humid equatorial climate. As it is always the rainy season on 1 side of the equator, the Congo River avoids any notable change in volume from alternating wet and dry seasons. By contrast, rivers in the savanna region of Africa often experience significant flow reductions during the dry season. Consequently, though only approximately 370 mile (600 kilometer) longer than the Niger river, the Congo River discharges nearly 8 times as much water into the Atlantic Ocean. Emptying into the ocean, the flow rate of the Congo River is second in the world behind only the Amazon River. However, as it is draining a basin in a humid equatorial climate, the tremendous discharge of the Congo River represents only 3 percent of its potential basin runoff. Looping north and west in a great arc from its headwaters in the Katanga province, the Congo River receives input from several substantial tributaries.

These rivers include the Kasai, Ubangi, Luvua, which emanates from Lake Mweru in the far southeast, and the Lualaba, the principal stream of the upper course, considered by many to be the main branch of the Congo. In its relentless journey to the Atlantic Ocean, the width of the Congo varies from 3.5 mile (8 kilometer) to 8 mile (12.8 kilometer) and is divisible into 3 distinct sections—the Upper, Middle, and Lower Congo. Characterized by waterfalls, lakes, and rapids, the Upper Congo includes a series of 7 cataracts and rapids known as Stanley Falls. Extending over 60 mile (96 kilometer), Stanley Falls demarcates the lower end of the Upper Congo and gives way to a lengthy stretch of navigable river along the Middle Congo. These navigable waters of the Middle Congo terminate just above Livingstone Falls and immediately downstream from the capital city of Kinshasha. A series of more than 30 cataracts, Livingstone Falls represents a turbulent 220 mile (354 kilometer) stretch of the Congo River.

Below the falls, the Lower Congo travels for approximately 200 mile (322 kilometer) across the nearly level coastal plain before terminating in the Atlantic Ocean. With an estuary approximately 7 mile (11 kilometer) wide, the Congo River differs from other African rivers such as the Niger and the Nile in that it does not form a significant delta upon entering the ocean. However, it is similar to its African counterparts in that it has only limited navigability for significant portions of its course. From its entry point into the Atlantic Ocean, for example, the Congo is navigable for only 85 mile (137 kilometer) before reaching a series of rapids at the major fishing port of Matadi. Despite its inherent difficulty, river transport is an even greater necessity in the waters of the Congo than elsewhere in Sub-Saharan Africa. This same turbulence that renders many stretches of the Congo River impassable also contributes to the river’s potential for hydroelectric power. Owing to the speed and volume of its waters, the Congo River basin is the potential source of approximately 13 percent of the world’s total hydroelectric power.

Inga Falls, some 25 mile (40 kilometer) upstream from the river port of Matadi, represents the largest hydroelectric power potential in Africa (and perhaps the world). Here water cascades downstream at a rate of 150,000 cubic foot (43,000 cubic meter) per second as the river falls nearly 330 foot (100 meter) in only 8.7 mile (14 kilometer). Efforts to tap into the estimated 43,000 megawatts of generating capacity have thus far captured only a fraction of the potential power. Completion of 2 construction phases, Inga I (1972) and Inga II (1982), has netted only 1,700 megawatts of hydroelectricity. In 1999, plans for additional Inga stages were announced—with the ultimate objective being the capture of the entire power of Inga Falls by 2010. Despite its hydroelectric potential, concerns have been raised over the project’s impact on the number of fish species and the viability of commercial inland fishing.

Like its river and tributaries, the entire Congo basin is difficult to traverse. Those pockets of the basin containing tremendous mineral wealth, including diamonds, cobalt and copper, have suffered intensive exploitation for decades. However, vast expanses of forest remain untouched and are home to such rare animals as the okapi and gorilla. Much of the forested basin has experienced only minimal human impact, such as when the Pygmies and other indigenous peoples use the forest for their hunting and gathering needs. Agricultural activity typically includes the cultivation of bananas, maize, and sweet potatoes, as well as more commercially oriented crops such as coffee and sugar. Other economic activity involves raising goats and tending livestock. Despite only fairly limited economic exploitation of the region, the mineral wealth and hydroelectric potential of the Congo River basin are likely to attract increasing attention and activity in the future. BIBLIOGRAPHY. Alan Grainger, "Forest Environments,” The Physical Geography of Africa, W.M. Adams, A.S. Goudie, and A.R. Orme, eds.

(Oxford University Press, 1996); Tom McKnight, ed., Geographica: The Complete Illustrated Atlas of the World (Barnes and Noble, 2001); Joseph R. Oppong, "Transport and Communication in Sub- Saharan Africa: Digital Bridges over Spatial Divides,” Geography of Sub-Saharan Africa, S. Aryeetey-Attoh, ed. (Pearson Education, 2003); Antony Orme, 1996. "Coastal Environments,” The Physical Geography of Africa (Oxford University Press, 1996); W.Y. Osei and S. Aryeetey-Attoh, "The Physical Environment,” Geography of Sub-Saharan Africa (Pearson Education, 2003); James R. Penn, Rivers of the World (ABC-CLIO, 2001). CHRISTOPHER CUSACK Amazon Facts | Project Amazonas Project Amazonas Amazon Facts Amazon Facts Amaze (or bore) your friends and colleagues with some Amazon trivia. Who knows, it might even win you big bucks someday on a game show! The Amazon IS the world's greatest river.

The Nile of Africa may be slightly longer, depending on how you measure each river, but for many other reasons the Amazon River is the undisputed title holder - the greatest river on the planet, in the solar system, and perhaps even in the Milky Way galaxy (at least no-one from planets orbiting Betelgeuse or Antares has yet provided convincing evidence that they have a bigger river on their planet!). Read on! If size is important to you... The average discharge of water into the Atlantic Ocean by the Amazon is approximately 175,000 m3 per second, or between 1/5th and 1/6th of the total discharge into the oceans of all of the world's rivers! This discharge is 4-5 times that of the Congo River (the second largest in ocean discharge), and 10 times that of the Mississippi. The Rio Negro, a tributary of the Amazon, is the second largest river in the world in terms of water flow, and is 100 meters (over 300 feet) deep and 14 kilometers (~9 miles) wide near its mouth at Manaus, Brazil. Raindrops keep falling on my head!

Average rainfall across the whole Amazon basin is approximately 2300 mm (or ~7.5') annually. In some areas of the northwest portion of the Amazon basin, yearly rainfall can exceed 6000 mm (almost 20')! Where does all that water go? The water discharged into the Atlantic Ocean is actually only about 1/3rd of the water that falls in the Amazon basin as rain. Where does the other 2/3rds go? Up to half of the rainfall in some areas may never reach the ground, being intercepted by the forest and re-evaporated into the atmosphere. Additional evaporation occurs from ground and river surfaces, or is released into the atmosphere by transpiration from plant leaves. All of this moisture re-enters the water cycling system of the Amazon, and a given molecule of water may be "re-cycled" many times between the time that it leaves the surface of the Atlantic Ocean and is carried by the prevailing westerly winds into the Amazon basin, to the time that it is carried back to the ocean by the Amazon River.

The Andes Mountains that border the west side of the Amazon help to ensure that most of the moisture stays in the system - very little is carried by the prevailing winds over the Andes to the Pacific Ocean. A long and winding river road. The total length of the Amazon River from its source springs in the Andes (taking the Ucayali River as the continuation of the main river into the Andes), is estimated at 6518 km ( ~4075 miles) (not including all river bends, and measuring the short distance around Marajó Island in the mouth of the Amazon). This is exceeded only by the Nile River (including the Kagera River) of Africa with a total length of 6671 km (4170 miles). If you measure the long-way around Marajo Island, however, the Amazon is slightly longer than the Nile! The Amazon headwaters are located high in the Andes at an elevation of about 5,200 meters (17,000 feet), and only 190 kilometers (120 miles) from the Pacific Ocean. Like mother, like daughters....

Two of the tributaries of the Amazon, the Juruá and the Madeira Rivers, are both over 3,300 km (2,060 miles) long. About 1,100 other sizeable tributaries empty into the Amazon River. Talk about a big mouth! The mouth of the Amazon is over 320 km wide (approximately 200 miles), and contains the worlds largest freshwater island, Marajó Island, with an area of 48,000 km2 (about the size of Switzerland). Momma was not a Rolling Stone! After leaving the Andes, the elevational gradient of the Amazon is very low. Iquitos, Peru is some 3,600 km (2,250 miles) from the Atlantic, yet the river-level at low-water season is only about 100 m (a bit more than 300') above sea-level, and the slope is around 2 cm (less than one inch) vertical change per kilometer.

In the lower Amazon, at the mouth of Rio Negro and still 1,500 km from the Atlantic, the river-level at low-water season is only 15 m (~47') above sea-level, and the slope is about 1 cm per kilometer. You won't find any white-water rapids along the main channel of the Amazon, though the sheer weight of the mass of water moves it along at a surprising speed. NEWS FLASH!! Rumpelstiltskin Drowns in Slow Flood. The Amazon is not a good place to fall into a long deep sleep on the river bank! Seasonal water levels can vary up to 20 meters (65 feet) in the middle Amazon region. Towards the mouth of the Amazon, the yearly change becomes less and less, but even near the mouth of the Amazon (at the Rio Xingu), it is still 4 meters (12 feet). In the Iquitos region of Peru, the annual change in river levels is about 15 meters (~50'). Flooded but not drowned. The seasonal variation in water levels means that huge areas along the major rivers in the Amazon basin are flooded annually.

The total area of flooded, or varzea, forest is between 50-60,000 km2, or about 4% of the total area of the Amazon rainforest. These flooded forest areas may extend as much as 80 kilometers (50 miles) from the main river channels, and the forest vegetation of the varzea is well adapted to being seasonally flooded. The structure and species composition of the varzea is very different from non-flooded upland (or terra firme) forest areas. Varzea forest areas are critical to the freshwater fisheries of the Amazon Basin. Go with the flow. Despite the low slope of the Amazon, the river currents can be surprisingly strong. In the lower Amazon (with the lowest slope), current speeds range from 0.5-1.0 meters per second at low water, and twice that at flood stage. In localized areas, current speeds can reach as high as 3 meters (9.8 feet) per second. Ships on a submarine river? The width of the Amazon at Iquitos, Peru (3,600 km/2,250 miles from the ocean) is about 2 km.

Ocean-going ships can easily access the Port of Iquitos at high water, as the mean depth of the current-canal of the Amazon is between 40 and 50 m (or up to 150+ feet deep), and in places, over 100 m (over 300 feet) deep. Even hundreds of miles away from the ocean, sections of the bottom of the river channel actually lie below sea level! World's Biggest Outhouse! In the Atlantic Ocean beyond the mouth of the Amazon, and resting on the continental shelf, the Amazon sediment cone has a length of about 680 km and a width of 250 km. These fine grained deposits (mostly clay/mud particles) on the ocean floor are over 11,000 meters (36,000 feet) thick. This is mostly sediment that has been carried downriver from the Andes Mountains, the Guianan Shield (to the North) and the Brazilian Shield (to the south), by the river current, and which settled out of the water column once the river current dissipated into the waters of the Atlantic Ocean. World's Biggest Washtub.

The Amazon basin (the watershed of the Amazon River) is 7,050,000 km2 in area (or about 2,500,000 miles2), and covers about 40% of South America. Of this area, approximately 5,000,000 km2 is (or was) covered by high tropical rainforest, with the remainder covered by savannah ("campo") or scrubby woodland ("cerrado"). The Amazon basin covers significant portions of the countries of Brazil, Peru, Colombia, Ecuador, Venezuela and Bolivia, though the major part of the watershed lies within Brazil. The next largest tropical watershed, that of the Congo River, at 3,690,000 km2, is only half the size of the Amazon basin. Violent Revolution Rocks South America! Although it now empties into the Atlantic Ocean, the Amazon once flowed into the Pacific! The uplift of the Andes Mountains about 65 million years ago in a geological event called the Laramide Revolution cut the flow to the Pacific, and forced the Amazon River to flow eastward.

This revolution took place when the westward-moving South American (geological or tectonic) plate crashed headlong into the eastern-moving Nazca Plate. The Nazca plate was forced beneath the South American plate, lifting up the Andes mountains in a process that continues to this day, as evidenced by the many earthquakes and high volcanic activity of the Andes region. But It's a Dry Heat... The Amazon basin has not always been an area of lush tropical rainforest. At several times during its history, the basin has been the location of huge lakes and shallow seas. Salt deposits up to 600 meters thick (nearly 2000 feet!) have also been found in some locations, indicating that at one time, the basin may have been desert-like, drying up the shallow seas and creating the salt deposits. A Well Watered Desert! Would you believe that the Amazon River has its own sand dunes? Echogrammes of the river bed below the mouth of the Rio Negro show giant sand dunes as long as 600 meters (2000 feet) and up to 12 meters (39 feet) in height.

These dunes are gradually moved downstream in the same manner that wind moves sand-dunes in "true" deserts! A Bouillabaisse of Fishes. The Amazon basin is home to over 2,500 species of fish, more species than are recorded for the entire Atlantic Ocean, and some experts estimate that there may be as many as 6,000 species! These range from giant 3-meter air-breathing fish (Arapaima gigas) and river catfish weighing up to 600-700 lbs, to tiny tetras, electric eels, sting-rays, needlefish, fresh-water flying-fish, and knife-fish. The fish fauna of many river systems is poorly known, and new species are discovered yearly, even in the "better-known" areas! Many of the above "Amazon Facts" are adapted from the following sources: The Amazon. Limnology and Landscape Ecology of a Mighty Tropical River and its Basin. (1984) H. Sioli, editor. Dr. W. Junk Publishers, Dordrecht (ISBN 90-6193-108-8). The Palms of the Amazon.

(1995) A. Henderson. Oxford University Press, Oxford, 362 pages. (ISBN 0-19-508311-3). Field Guide to the Palms of the Americas (1995; A. Henderson, G. Galeano and R. Bernal; Princeton University Press, Princeton, New Jersey; ISBN 0-691-08537-4) A Neotropical Companion. 2nd Ed. (1997) J. C. Kricher. Princeton University Press, Princeton, New Jersey, 451 pages. (ISBN 0-691-04433-3 See the Recommended Reading page for many more great sources of information. The Congo River The Congo River  Geography links The Congo is the world's eighth-longest river at 2,914 miles long. It begins at the junction of the Lualaba and Luvua rivers, in the Altai Mountains, and flows southwest to the Atlantic Ocean. Major tributaries include the Aruwimi, kasai, and Lomami rivers.

The river forms most of the border between Zaire and the Republic of Congo and drains more than 1,600,000 square miles of land. The river has a width in a range of 0.5 to 10 miles. The Congo River gets up to 90 inches of rainfall a year. It has within its banks 30 waterfalls and thousands of islands, at least 50 of which are more than 10 miles in length. Because the river flows for the most part near the Equator, the area around it is very hot. Much of the land surrounding the river is tropical rain forest and is home to hundreds of kinds of animals, including hippos, manatees, water snakes, crocodiles, tortoises, pigs, elephants, and 200 species of fish. In addition, insects such as mosquitoes and gnats are prevalent in the hot, humid conditions. It's not all tropical rainforest, though. Some parts of the surrounding land are full of long grass called "barnyard grass." Many animals graze in this tall grass, including buffalo, antelopes, zebras, gazelles, and giraffes.

People live along the river and in the river basin as well. They fish in the river. They use it for irrigation to help water their peanut, cotton, tobacco, and sugarcane crops, all of which grow quickly in the humid air. Just as has been done for hundreds and hundreds of years, people today use the Congo River for transportation, of both people and goods. It is not an uncommon sight to see a barge that is carrying wood or fuel or crops going up or down the river. With gasoline-powered barges, however, comes pollution. Facts About the Congo River Length

Question: Into which ocean does the river Congo flow
Answer: Atlantic